A novel technology of “long excavation/ long detection” for rapid excavation in coal mine roadway

The low efficiency of coal mine roadway excavation is the main cause for the imbalance between coal mining and heading. The geological factor of low excavation efficiency is that the advance detection distance of the excavated roadway is short,the accuracy is low,and the existing detection methods are inconsistent with the excavation work in time,working space and detection environment.Therefore,the conventional “short excavation and short detection” technology cannot meet the technical requirements of long distance and high precision geological advance detection for rapid roadway excavation.The “long excavation and long detection” technology is based on the main hole and branch hole constructed by the kilometer directional drilling machine in the coal mine to realize the long distance detection of the occurrence form of the coal seam in front of the excavated roadway and the hidden geological factors causing disasters.In the directional long borehole,some new borehole geophysical exploration technologies such as borehole transient electromagnetic,borehole radar and azimuth natural gamma logging are used to detect the geological structures and watery zones within 30m in the radial direction of the borehole.This meets the geological needs of long distance,high precision and allround structural detection and hidden danger investigation in front of the rapid excavated roadway.The engineering practice shows that the “long excavation and long detection” technology based on “directional long drilling plus borehole geophysical exploration”can carry out“long distance”detection along the heading direction and close range high precision detection around the roadway,which provides a geological basis for safe and rapid roadway excavation.The technology developed solves the conflict between advanced detection and rapid excavation in excavation time,working space and detection environment. In addition,it meets the detailed rules and regulations for water prevention and control,and helps to improve the effective time of rapid roadway excavation,with good technical adaptability and wide promotion value,and also will provide a reliable geological guarantee for the high precision long distance advanced detection of rapid roadway excavation in coal mine in the future.